Approach to vomiting (chronic): Clinical sciences

Vomiting refers to the forceful expulsion of the stomach contents caused by humoral stimulation of the chemoreceptor trigger zone or neural stimulation of the emetic center. If it persists for four weeks or more, that’s chronic vomiting. Based on the presence of abdominal symptoms, causes of chronic vomiting can be categorized into abdominal and non-abdominal ones.

If a patient presents with chronic vomiting, first perform an ABCDE assessment to determine if they are unstable or stable.

If unstable, stabilize the airway, breathing, and circulation. Next, obtain IV access and administer IV fluids. Put your patient on continuous vital sign monitoring including heart rate, blood pressure, and pulse oximetry, and if needed, provide supplemental oxygen.

Also, keep in mind that unstable patients might have electrolyte abnormalities, acid-base disturbances, or signs of severe dehydration.

Let’s move on to stable patients. Your first step is to obtain a focused history and physical examination and order labs, including a CMP.

Your patient will report persistent vomiting for more than four weeks, usually associated with nausea and changes in bowel habits. Physical exam might reveal abdominal tenderness and distension, as well as poor skin turgor and dry mucous membranes.

Labs might show electrolyte disturbances like hypokalemia or hyponatremia, elevated bicarbonate level, and renal insufficiency. With these findings, think about abdominal causes of chronic vomiting.

Here’s a clinical pearl! Pregnancy is a can’t-miss cause of nausea and vomiting! If your patient is a biological female of child-bearing age, order a urine pregnancy test. Vomiting in pregnancy can range from mild to severe disease and hyperemesis gravidarum, which may even require hospitalization.

Other causes of chronic vomiting include medications like opioids, antibiotics, chemotherapeutic agents; and substances like alcohol and cannabis, which can cause cannabinoid hyperemesis syndrome.

Okay, the first abdominal cause is peptic ulcer disease or PUD. These patients typically report epigastric pain that worsens after eating, early satiety, and sometimes, hematemesis or melena. Physical exam might reveal epigastric tenderness and pallor. At this point, consider PUD and obtain a CBC and an esophagogastroduodenoscopy, or EGD. If the CBC reveals anemia and the EGD shows a gastric or duodenal ulcer, diagnose PUD.

Next up is inflammatory bowel disease, or IBD. If your patient reports crampy abdominal pain, diarrhea, and possibly hematochezia, and the exam reveals diffuse abdominal tenderness, consider IBD. Then, obtain a CBC and colonoscopy. CBC often shows anemia, while colonoscopy will reveal either signs of ulcerative colitis, such as continuous mucosal inflammation, or Crohn disease, like transmural skip lesions. You might also note histologic granulomas. If you see these findings, diagnose IBD. Keep in mind that vomiting in IBD can be a sign of obstruction.

On that note, let’s talk about mechanical obstruction. These patients generally report crampy abdominal pain that is worse after eating, early satiety, and in some cases, constipation or intractable obstipation, which is caused by prolonged retention of hard, dry feces that can even block the passage of gas. Exam findings include abdominal tenderness and distention, and possibly a palpable mass.

With these findings, consider mechanical obstruction and order a CT of the abdomen. If you see signs of obstruction, such as a mass, bowel wall thickening, as well as distention with an air-fluid level proximal to the obstruction, diagnose mechanical gastrointestinal obstruction.

Here’s a clinical pearl! Even though you’ve diagnosed an obstruction as a cause of chronic vomiting, in some cases you’ll need additional tests to reach your final diagnosis. For example, if colon cancer is suspected, additional steps like a CT scan of the chest, tumor markers, and colonoscopy with biopsy should be completed.

Next, let’s talk about chronic pancreatitis. Patients typically report upper abdominal pain that can range from constant and dull, to acute and stabbing that sometimes radiates to the back and is relieved by leaning forward. They might also report fatty stools that are difficult to flush, abdominal bloating, and unexplained weight loss. Exam will reveal epigastric tenderness. At this point, consider chronic pancreatitis and order labs, including lipase and fecal elastase; and CT of the abdomen. Lipase is elevated in many cases, but not always, while fecal elastase is decreased, indicating pancreatic secretory insufficiency. CT will reveal “chains of lakes” sign, which are dilated pancreatic ducts and extensive parenchymal calcifications. With these findings, diagnose chronic pancreatitis.